Manipulators, particularly in automated form as multiple industrial robots, hereinafter called robots for short, are nowadays used in many different fields of technology. When using such robots in contamination-endangered environments, such as in the food processing industry or pharmaceutical industry, it must be very strictly ensured that there is no infringement of hygiene regulations as a result of the release of abrasive particles and/or lubricant vapours. A source for such contamination is in particular the joint areas of the robot, in which are located the drive units for the moving parts of the robot with their motors and various components moved relative to one another, which also leads to the presence of lubricants and open interfaces in the robot structure, so that at these points the indicated contamination effects occur, particularly due to friction effects.
In order to counteract a restriction to the usability of the robot as a result of this, WO 00/29177 proposes surrounding the entire drive mechanisms of a robot with a pressure-tight casing and to ensure therein a closed cooling gas flow for cooling purposes.
It is particularly disadvantageous in this connection that as a result of the cladding of the entire manipulator, particularly in the case of a six-axial industrial robot, a considerable restriction to the mobility of the manipulator must be expected. Due to the closed flow path in WO 00/29177, it is not possible to remove from the interior of the casing moisture and other contaminations, so that bacterial concentrations can possibly arise there and therefore there is an increased contamination risk.
It is also known in connection with robots for explosion protection purposes, to house the entire robot or some of its drive units in a sealed casing. EP 203 202 A1 discloses an industrial robot, in whose interior is provided a cohesive scavenging area for the drive units subject to the action of a pressure medium. In EP 245 530 A1 a motor means for a robot hand is placed in a cladding subject to the action of a pressure medium. In DE 36 27 775 A1 drive units of an industrial robot are placed in individual, air-tight containers, into which the compressed air is introduced as inert gas.
The problem of the invention is to further develop a method and a manipulator of the aforementioned type in such a way that a reliable usability of the manipulator in contamination-endangered environments is rendered possible in a constructionally simple and therefore particularly inexpensive manner.